'Nearly unbreakable' encryption inspired by biology

A team of physicists has built a "nearly unbreakable" encryption
system devised using the same mathematical principles that explain
how the human heart and lungs function in unison.

The system has been described in a paper published in Physical Review X, penned by Tomislav
Stankovski, Peter McClintock and Aneta Stefanovska of Lancaster
University, and a patent has already been filed. The kicker is, not
one of the physics professors had experience in encryption. Their
joint backgrounds are in engineering, nonlinear dynamics and
biomedical/physics engineering, but when they read up on the latest
discoveries around the cardiorespiratory coupling function -- the
way in which the heart and lungs work together continuously -- the
potential applications became clear.

"Knowing about some of the open problems in encryption, we
suddenly realised that what we tried to understand in biology can
also be applied here," Stefanovska told Wired.co.uk. "Coupling"
essentially involves a time-varying delay, that when translated to
encryption systems means an infinite number of secret encryption
keys shared by the sender and recipient is possible. It means it is
"highly resistant to conventional methods of attack" according to
Stankovski.

Stefanovska explains: "The information signals are encrypted in
the coupling functions; i.e. they modulate the nonlinear coupling
functions between two dynamical systems (analogous to the heart and
lungs). Two signals, one from each system, are transmitted through
the public channel. At the receiver, knowing what those coupling
functions are, the process can be reversed."

The system also lowers the chances quite dramatically of any
interference and "random noise" that can weaken such communication
systems. "This makes it suitable for implementation not only for
landline but also for mobile and wireless communications, where the
level of external interference tends to be higher," write the
authors in Physical Review X.

The system has been rigorously tested, leading McClintock to
claim: "This promises an encryption scheme that is so nearly
unbreakable that it will be equally unwelcome to internet criminals
and official eavesdroppers." Stefanovska explains that the word
"nearly" is only used for the sake of caution -- to date, there
have been no possible breaches to the system identified.

The filed patent names Robert Young, a cybersecurity expert, as
a co-developer, and the team says so far "initial reactions were
positive" from industry experts.

When we asked Stefanovska about the impact such a system could
have in a post-NSA/GCHQ mass surveillance world, she responded:
"The potential certainly exists -- and the importance and relevance
is self-evident. It depends on the outcome of attempts to break the
encryption scheme. If it resists attack to the extent we
anticipate, there can indeed be real impact."